Current Hypertension Reviews - Volume 16, Issue 3, 2020

Reactive Oxygen Species (ROS) are reactive derivatives of oxygen metabolism. The ROS generation can be mediated by distinctive enzymatic systems including NADPH oxidases. The components of this enzyme are expressed in endothelial and vascular smooth muscle cells, adventitial fibroblasts, and infiltrating monocytes/macrophages. Oxidative stress is a molecular dysregulation in ROS generation/elimination, which plays a key role in the development of vascular dysfunction in distinctive conditions including hypertension. It is characterized by vascular inflammation, a loss of NO bioavailability and endothelial dysfunction. Considering that oxidative stress is a key mediator of vascular dysfunction, antioxidant therapy with classic antioxidants seemed to be a promising alternative for the treatment of vascular diseases. In this sense, some commonly used drugs for the treatment of cardiovascular diseases such as Angiotensin Converting Enzyme (ACE) inhibitors or angiotensin receptor AT1 antagonists showed antioxidant effects that might have contributed, at least in part, to the beneficial effects of these drugs on the treatment of cardiovascular diseases. The effectiveness of these drugs shows that ROS are in fact important mediators of vascular dysfunction and that angiotensin II plays a critical role in such response.

Background: Disruption of redox signaling is a common pathophysiological mechanism observed in several diseases. In hypertension, oxidative stress, resulted either from enhances in Reactive Oxygen Species (ROS) production or decreases in antioxidant defenses, is associated with increase in blood pressure, endothelial dysfunction and vascular remodeling. Although the role of oxidative stress in the development of hypertension is well known, it is still unclear if this process is a cause or a consequence of tissue changes in hypertension. Indeed, unbalanced ROS formation results in several detrimental effects that contribute to hypertension, including reduction in nitric oxide bioavailability and activation of metalloproteinases. Additionally, ROS may also directly react with lipids, proteins and DNA, thereby contributing to tissue damage associated with hypertension. Therefore, a deep understanding of the role of oxidative stress in hypertension is essential to comprehend its pathophysiology and to identify new therapeutic targets. Conclusion: This mini-review discusses the main enzymatic sources of oxidants and the major antioxidant defenses in the vasculature, followed by the effects of oxidative stress in hypertension, highlighting endothelial dysfunction, vascular remodeling and tissue damage.

Oxidative stress is implicated in the etiology of many ethanol-induced pathologies. Oxidative stress has been shown to contribute to the development of endothelial dysfunction and cardiovascular disease, such as hypertension. This review details mechanisms of vascular function, the role of oxidative stress in vascular biology and how ethanol consumption may alter endothelial and smooth muscle cell function as well as microvascular function. Also reviewed are data from human investigations that have examined the association between alcohol consumption and changes in blood pressure and increased risk for hypertension.

Most of the systemic blood vessels are surrounded by the perivascular adipose tissue (PVAT). Healthy PVAT is anticontractile and anti-inflammatory, but a dysfunctional PVAT has been suggested to link cardiometabolic risk factors to vascular dysfunction. Vascular oxidative stress is an important pathophysiological event in cardiometabolic complications of obesity, type 2 diabetes, and hypertension. PVAT-derived adipocytes generate reactive oxygen species (ROS) including superoxide anion and hydrogen peroxide that might signal to the vascular wall. Therefore, an abnormal generation of ROS by PVAT emerges as a potential pathophysiological mechanism underlying vascular injury. This review summarizes new findings describing ROS production in the PVAT of several vascular beds, major sources of ROS in this tissue including mitochondria, NADPH oxidase and eNOS uncoupled, and finally, changes in ROS production affecting vascular function in the presence of cardiometabolic risk factors and diseases.

The use of heavy metals is closely linked to the history of mankind. They have been used as important materials in a wide variety of human activities such as manufacturing utensils and tools. Such extended use has significantly increased professional and environmental exposure to mercury, lead and cadmium. These metals are known to produce hypertension in humans and animals and, among other effects, they can also affect endothelial function. Results described here suggest that mercury, lead and cadmium affect vascular reactivity, even at low doses or concentrations. Several vascular actions are mediated by the endothelium via increasing the production of free radicals and angiotensin II by local ACE stimulation. These results provide further evidence that these toxic metals, even at low doses, are an environmental risk factor to the exposed population. These results also suggest that continuous exposure to these metals, followed by their absorption and progressive accumulation in the body, may be hazardous to cardiovascular function. Therefore, the current reference values, which are considered safe, need to be reduced.

This article traces the history of the development of artificial intelligence as a science that constantly responds to current problems that arise in medical practice. Attention is drawn to the fact that almost all modern neural systems of medical diagnostics are static. This means that they do not have a time axis, and therefore, can only make diagnoses of diseases at the current time. As a result, doctors have to make prescriptions for prevention and treatment courses without checking on computer models what this may lead to in the future. Thus, consciously or unconsciously, doctors have to experiment on patients, which is an ethical problem. This article shows that this centuriesold ethical problem can be solved by further development and application of modern methods of artificial intelligence. Optimal selection of prevention and treatment courses can be made by virtual predictive experimentation on dynamic computer models of patients.

Background: Preeclampsia is multi-systemic hypertensive pregnancy disorder accompanied by proteinuria. Objectives: To determine the frequency of different presentations of preeclampsia in tertiary care hospital and find out its risk factors. Materials and Methods: The present study was hospital-based cross-sectional study and conducted from 1st August 2015 to 31st July 2016 in Gynaecology and Obstetrics Department, Liaquat University of Medical and Health Sciences (LUMHS), Hyderabad after ethical approval. A total of 112 pre-eclamptic women were enrolled during the study period by non-probability consecutive sampling. Patients were divided on the basis of their presentations into mild preeclampsia, severe preeclampsia, antepartum eclampsia, intrapartum eclampsia, HELLP syndrome, postpartum preeclampsia, postpartum eclampsia and atypical preeclampsia/eclampsia. All the sociodemographic factors and clinical variables were noted. Frequency and percentage were calculated for categorical variable and mean/standard deviation (SD) for continuous variables. Results: Of the 112 preeclamptic women, 54.5% were admitted with antepartum eclampsia, 12.5% with severe preeclampsia, 8.9% with atypical preeclampsia/eclampsia, 8% with mild preeclampsia, 8% with postpartum eclampsia, 3.6% with HELLP syndrome, 2.7% with intrapartum eclampsia and 1.8% with postpartum preeclampsia. Overall, majority of the patients were primigravida (57%), had gestational age >34 weeks at presentation (58.9%) and < 7 antenatal visits (88.3%) during their pregnancy. Overall 17.8% had previous bad obstetrical events, 11.6% had previous history of preeclampsia and 64.3% had consanguineous marriages. Conclusion: Different presentations of preeclampsia may help obstetricians to rule out high- risk pregnancies and provide antenatal care to patients earlier to prevent complications to both mother and fetus.

Background: Pre-eclampsia is a hypertensive pregnancy disorder accompanied by proteinuria. Serum Lactate Dehydrogenase (LDH) is a biochemical marker that reflects the severity and progression of pre-eclampsia. Methods: A cross-sectional study was conducted at the Liaquat University of Medical and Health Sciences (LUMHS). One hundred pre-eclamptic women were enrolled and categorized into mild (n=30) and severe pre-eclamptic groups (n=70) to ascertain the function of LDH as a prognostic marker and to assess its association with severity and gestational age in pre-eclamptic women. Results: The significant differences in mean concentrations of LDH between mild and severe preeclamptic women (p-value <0.0001) and early and late-onset pre-eclamptic women (p-value=0.049) were found. Significant differences were also found in the LDH range between mild and severe preeclamptic women presented with late-onset pre-eclampsia (p-value= 0.004). Statistically significant differences (p-value= 0.019) in the levels of LDH were found with systolic blood pressure and proteinuria (p-value= 0.048). Conclusion: LDH is the prognostic marker representing the severity of pre-eclampsia. An increased level of LDH directs adequate monitoring and management; and by early detection of preeclampsia, serious consequences and complications may be prevented.

Background: Arterial hypertension is among the leading causes of mortality worldwide. The primary non-pharmacological management of arterial hypertension is isometric grip training, which has shown better results than pharmacological methods; however, it has not been thoroughly studied in large muscle groups. Objective: This study compared the pressor response of isometric exercise training at different intensities, in large groups versus small muscle groups, in sedentary eutrophic and overweight people aged 20-29 years. Methods: A sample of 93 people (57 people with excess weight and 36 people of normal weight) participated in isometric training for 5 days, subdivided into leg press vs. handgrip strength, with different intensities for each subgroup (30 and 50%, 1 RM). Before and after the 5 training days, Heart Rate Variability (HRV) and systolic and diastolic blood pressure, BSBP-BDBP and PSBP-PDBP, were measured to evaluate the state of sympathetic activation at rest and pressor response. Results: Changes with significant differences (p <0.05) in terms of pre-post training measurements in the eutrophic group were the BSBP-PSBP variables at 30% and 50% 1 RM for manual isometric grip strength. In the excess weight group, the only significant change was the PSBP variable in handgrip strength at 30% 1 RM. It should be noted that in all cases, blood pressure values reduced. Conclusion: Isometric strength exercises in large and small muscle groups show a tendency to reduce blood pressure values; however, the isometric handgrip force at 30% 1 RM shows statistically significant reductions in blood pressure values.

Background: In the trial known as COPE (Combination Therapy of Hypertension to Prevent Cardiovascular Events), three benidipine (a Calcium Channel Blocker; CCB) regimens were compared. Hypertensive Japanese outpatients aged 40–85 years (n=3,293) who did not achieve the target blood pressure of <140/90 mmHg with benidipine 4 mg/day were treated with the diuretic thiazide (n=1,094) or a β-blocker (n=1,089) or an additional Angiotensin Receptor Blocker (ARB; n=1,110). A significantly higher incidence of hard cardiovascular composite endpoints and of fatal or non-fatal strokes was observed in the benidipine-β-blocker group compared to the benidipine-thiazide group. Objective and Methods: We further evaluated the treatment effects of the three benidipine-based regimens on vascular and renal events in a sub-analysis of the COPE patients. Results: A total of 10 vascular events (0.8 per 1,000 person-years) including one aortic dissection (0.1 per 1,000 person-years) and nine cases of peripheral artery disease (0.8 per 1,000 person-years) were documented, as was a total of seven renal events (0.6 per 1,000 person-years). No significant differences in vascular and renal events were revealed among the three treatment groups: vascular events, p=0.92; renal events, p=0.16, log-rank test. Conclusion: Blood pressure-lowering therapy with benidipine combined with an ARB, β-blocker, or thiazide was similarly effective in the prevention of vascular and renal events in hypertensive outpatients, although there are not enough events to compare the difference in the three treatment groups.